Many communication switch and router systems architecture provide redundant communication capabilities. Lucent Technologies, Murray Hill, N.J. has announced a redundant system under its MSC 25000 Multiservice Packet Core Switch (trade-mark of Lucent Technologies). Marconi plc, London, England has announced a redundant system under its BXR 48000 router (trade-mark of Marconi plc).
Redundancy in a router system can be provided on two levels. A first level provides redundancy within a single shelf for a communication switch. Therein, two or more modules provide redundant communication capabilities for another communication module on the same shelf. A second type of redundancy provides fabric redundancy beyond the switch matrix cards and includes fabric interface cards (FICs) installed on input/output (I/O) shelves, high-speed inter-shelf links (HISL) cables connecting I/O shelves and Switch Access Cards (SACs) installed in switching shelves.
In addition, any fabric redundancy implementation may need to comply with Bellcore standards when executing a complete datapath switchover. The current Bellcore standard mandates that a switchover must be completed within 60 ms upon detection of a fault in any switching fabric. Further, software detection of an error should occur within 20 ms (non Bellcore specification).
Prior art systems providing fabric redundancy do not provide a flexible method of tracking the location of errors in a switching fabric and do not provide an indication where faults occurred and how the switching mechanism reacted to faults.
Further, prior art redundancy systems do not enable particular fabrics to be isolated to prevent that fabric from causing fabric switchovers.
Further, prior art systems do not provide a mechanism to recover automatically from control path isolation or shelf controller resets.
There is a need for a system and method providing switching redundancy that improves upon the prior art systems.